title: Assessment of geographical variation in the respiratory toxicity of desert dust particles.
abstract: The health consequences of sand particle inhalation are incompletely understood. This project evaluated the respiratory toxicity of sand particles collected at military bases near Fort Irwin USA, in Iraq (Camp Victory, Taji and Talil), and Khost Afghanistan. Our primary focus was on assessing the role of soluble metals in the respiratory toxicity of the sand particles using in vitro and in vivo methods. Replicating rat type II alveolar cell cultures (RLE-6TN) were exposed to sand extracts or vehicle control in serum-free media for ≤24 h. Cytotoxicity was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and assessment of lactate dehydrogenase leakage. The relative in vitro cytotoxicity of the sand extracts was Taji ≈ Talil > Afghanistan > Camp Victory ≈ Fort Irwin. We also assessed extracts of Camp Victory, Afghanistan, and Taji sand for acute and delayed pulmonary toxicity in rats following intratracheal administration. Assessments included biochemical analysis of bronchoalveolar lavage fluid (BALF) and lung histopathology. The in vitro cytotoxicity assay results were partially predictive of in vivo responses. The more cytotoxic Taji sand extract induced an acute irritant response in rats following intratracheal administration. Rats given the less cytotoxic Camp Victory sand extract had minimal biochemical or cytological BALF changes whereas rats given either the Afghanistan or Taji sand extracts demonstrated BALF changes that were suggestive of mild lung inflammation. Unexpectedly, we observed similar lung pathology in all extract-exposed rats. The results of our study can be used to prioritize future particle inhalation studies or guide epidemiological study design.
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Taylor
authors.forename: Melanie L
authors.initials: ML
authors.lastname: Foster
authors.forename: J McHugh
authors.initials: JM
authors.lastname: Law
authors.forename: Jose A
authors.initials: JA
authors.lastname: Centeno
authors.forename: Elisa
authors.initials: E
authors.lastname: Fornero
authors.forename: M Stephen
authors.initials: MS
authors.lastname: Henderson
authors.forename: Sabrina A
authors.initials: SA
authors.lastname: Trager
authors.forename: Michael G
authors.initials: MG
authors.lastname: Stockelman
authors.forename: David C
authors.initials: DC
authors.lastname: Dorman
mesh_terms: D000280:Administration, Inhalation; D000346:Afghanistan; D000818:Animals; D001151:Arsenic / Q000032:analysis / Q000633:toxicity; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002452:Cell Count; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D004391:Dust / Q000032:analysis; D004731:Endotoxins / Q000032:analysis / Q000633:toxicity; D005843:Geography; D007493:Iraq; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008670:Metals / Q000032:analysis / Q000633:toxicity; D051381:Rats; D012822:Silicon Dioxide / Q000032:analysis / Q000633:toxicity*; D014481:United States
chemical_list: D016207:Cytokines; D004391:Dust; D004731:Endotoxins; D008670:Metals; D012822:Silicon Dioxide; D007770:L-Lactate Dehydrogenase; D001151:Arsenic